There has been proposed a vehicle alarm device that when the traveling vehicle departs from the lane, cautions (notifies) the driver by vibrating the driver's seat (see Patent Literature 1, paragraph [0029], FIGS. 1 and 2). This vehicle alarm device has vibrators installed in right and left positions of the seat surface of a seat. If the vehicle crosses the right lane marking, the vehicle alarm device vibrates the right vibrator; if the vehicle crosses the left lane marking, it vibrates the left vibrator.
There has been also proposed a vehicle alarm device that notifies the driver of directional information by causing multiple vibrators installed in slightly spaced positions of a seat frame to sequentially generate vibration and thus giving progressiveness to the vibrations (generating a vibration wave) (see Patent Literature 2, paragraphs [0064] to [0067], FIGS. 5 and 6).
These vehicle alarm devices allow the driver to feel, through a vibration, a caution (notification, alarm) issued in accordance with the situation of the vehicle.